perf/x86: Save a few bytes in 'struct x86_pmu'

All these are basically boolean flags, use a bitfield to save a few
bytes.
Suggested-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-vsevd5g8lhcn129n3s7trl7r@git.kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/perf_event.h

@@ -374,8 +374,11 @@ struct x86_pmu {
 	/*
 	 * Intel DebugStore bits
 	 */
-	int		bts, pebs;
-	int		bts_active, pebs_active, pebs_broken;
+	int		bts		:1,
+			bts_active	:1,
+			pebs		:1,
+			pebs_active	:1,
+			pebs_broken	:1;
 	int		pebs_record_size;
 	void		(*drain_pebs)(struct pt_regs *regs);
 	struct event_constraint *pebs_constraints;